1. Field of the Invention
The invention is directed to an improved magnet valve for use in a traction-controlled hydraulic brake system for a vehicle.
2. Description of the Prior Art
One magnet valve is already known (German Patent Disclosure DE 198 07 130 A1), in which a hydraulic part of the magnet valve is received in a bore of a valve block. An electrical part of the magnet valve is slipped onto the hydraulic part, the latter protruding from the valve block.
The hydraulic part of the known magnet valve has an armature guide sleeve, which toward the valve block is widened with an annular shoulder, for the fluid-tight reception of a multi-part valve body with a valve seat of a seat valve. A securing bush is slipped onto the armature guide sleeve. This securing bush fittingly embraces the armature guide sleeve above the annular shoulder and also embraces both the annular shoulder itself and a following, widened sleeve portion, in the case of these latter two doing so with a fluid-tight press fit. The securing bush is also calked to the armature guide sleeve in the region of the orifice of this guide sleeve, which entails increased assembly effort and expense. The hydraulic part, which is completed with an armature, a restoring spring, a pole core and a filter disk, is braced with the securing bush on a step in the bore of the valve block. Calking the securing bush on the outer circumference on the valve block serves to secure and seal off the hydraulic part in the fluid-carrying bore.
It is also known from German Patent Disclosure DE 197 10 353 A1 to equip the hydraulic part of a magnet valve with a cup-shaped valve sleeve, which on its bottom is provide with a valve seat of a seat vavle, which valve seat is created without metal-cutting machining. The vavle sleeve engages a portion of the bore of a valve block with a circumferential press fit in fluid-tight fashion and separates fluid-carrying conduits whose passage can be switched with the seat valve. This makes it possible to dispense with an additional sealing element.
The magnet valve of the invention has the advantage over the first valve described above in that a fluid-tight communication between the guide sleeve and the securing bush is achieved simultaneously with the slipping of the bush onto the sleeve to generate the press fit, and that the edge of the securing bush, on striking the throat of the guide sleeve, undergoes a reshaping process that leads to an intimate conforming of the guide sleeve and the securing bush in this zone. In this pressure-reshaping, the throat is the tool, and the edge is the plastically deformed workpiece. By means of this design, it is economically possible in a single assembly operation both to secure the bush on the guide sleeve and to provide sealing between the two parts.